Loom bumper strap



Aug. 28, 1956 G. K. HUSSEY 2,760,526

LOOM BUMPER STRAP Filed March 16, 1953 14 14 12 14 10 1 10 P 2 &

INVENTOR. GARDNER HUSSEY AT TORNEIZ LOOM BER STRAP Gardner K. Hussey, Wakefield, Mass, assignor to Grater! & Knight Company, Worcester, Mass, a corporation of Massachusetts Application March 16, 1953, Serial No. 342,340

1 Claim. (Cl. 139-166) This invention relates to a loom bumper strap and a method of making the same, and more particularly to a resilient corrugated member arranged to receive the impact of the shuttle throwing picker.

In one type of loom. the shuttle is thrown through the shed by a picker which is slidably mounted on a rod arranged parallel with the shuttle movement. The picker is carried forward by a picker stick and the impact is transferred to throw the shuttle. When the shuttle is thrown, the picker momentum is absorbed by a resilient loom bumper strap which is the subject matter of my invention.

One type of bumper strap is made of a long piece of stiff leather or of suitably reinforced leather, such as is shown in the patent to Lesesne #2,499,596 of March 7, 1950. The strap indicated in the drawings is shaped initially as a straight piece and it is bent when intended to be mounted on the loom picker rod to form a multiplicity of S-shaped corrugation loops, and central perforations through these loops serve for mounting the corrugated strap on the picker rod. The momentum of the picker is large and its impact severe. Hence it is required that the bumper strap have a high stiffness or resistance to the blow and yet be sufliciently resilient to absorb the same. The initial stiffness of the straight piece of leather is such that it is difiicult to bend the strap, and it is customary to form and thread only one or two of the loops of the strap on the picker rod at first; and then as the leather becomes softer and more flexible and at the same time loses some of its resiliency, a further loop of the strap is formed and threaded on the rod.

One object of my invention is to provide a loom bumper strap which may be assembled initially on the picker rod in its final form so as to minimize the delays and expense involved in shutting down the loom for making a change in the shape of the strap.

It is, however, found that if it is attempted to bend the strap and form the full number of loops and then assemble the looped strap on the picker red when in its initial stiff condition, the machine operator has to hammer the leather into place or employ clamps to bend it to fit on the rod. This serves to break or weaken the leather fibres and shorten its lift or render it useless.

A further object of this invention is to provide a performed bumper strap which is shaped for readily sliding upon the picker rod without requiring undue force.

A still further object is to provide a preformed picker strap which has been so treated as to protect the leather fibres against the weave room humidity as well as oils and greases.

Another object is to provide a method of preforming the bumper strap and of so conditioning the leather that it may be readily slid onto the picker rod. Further objects will be apparent in the following disclosure.

Refcrring to the drawings which illustrate one embodi ment of this invention:

Fig. 1 is a perspective view of a preformed and re- Patented Aug; 28, 1956 inforced leather strap which is mounted on a removable dowel pin and held in position for sliding onto the picker rod; 7

Fig. 2 is a top plan view of an apparatus arranged for preforming the required loops in the strap and having assembled thereon the formed strap, shown partly in section and in a plan View; and

Fig. 3 is a fragmentary sectional view taken through the slot 17 showing a modified form of strap which has been impregnated and coated with a water impervious compound.

The strap may initially comprise a straight strip of leather which may be shaped to the required fiat form. The strap is preferably formed of at least one strip of leather and preferably two strips of leather 1t and 11 having mounted therebetween a layer 12 of a resilient body, such as a stiff cotton or duck fabric of coarse yarn, such as a No. 8 or 10 duck, which is preferably waterproofed as by rubberizing the same or impregnating it with a wax. The strap, whether made of a single piece of leather or of a laminated structure, is shaped to provide a required number of loops, such as the five adjacent loops 14- indicated in Fig. 1. To limit the longitudinal extension of the looped structure, as well as to add strength, one end portion 15 of the strap may be brought around from one end loop to have its end portion 16 lie against the loop at the opposite end of the strap; As indicated, the strap is provided with either circular or preferably elliptical slots or holes it? which are so located that when the strap is bent into its final form, these holes are in alignment and may be mounted on the picker rod, as well as on a removable dowel pin 18 which aids in maintaining the corrugated shape.

One suitable strap may comprise initially a straight strip of leather 18 or 20 inches long and approximately inch in thickness and about 1 /2 inches or more wide, and this strip may be used alone or in a laminated structure which may be made according to said Lesesne patent or by laminating the leather with one or more layers of a stiff cotton duck. In the preferred form, at least one layer of leather is employed with, and preferably cemented to, a resilient fabric body 12, preferably cotton canvas, nylon or rayon, having at least one layer of fabric, and preferably two or more, which may be reudered stiifly resilient by a suitable elastomer, such as natural or synthetic rubber, impregnating the fibres and filling the weave pore spaces. This fabric body retains resiliency after the leather has softened in use and so increases the useful life of the trap. Other types of resilient material may be used in place of the fabric; Also, the fabric layer may be left unimpregnated except as affected by a coating of cement, such as rubber or various elastomers, which secures the fabric to the leather. The fabric may be cemented to the leather by a flexible glue or by nitrocellulose in an acetone solvent or by vinyl polymers, such as vinyl acetate in acetone.

The toughest and best of leather is ordinarily used for making the strap because of the very severe requirements that it must meet, and this leather alone or the assembly of leather with a resilient fabric or other suitable strip is therefore very stiff and difficult to bend into the shape shown in Fig. 1 without an initial leather treatment. To this end, I release the rigidity of the leather fibres or soften the leather initially with a suitable agent, such as water, steam or other leather softening evaporable material applied at a suitable temperature. By thoroughly impregnating the leather with water, for example, at roo mtemperature, the leather is ultimately brought into a soft, pliable and moldable condition. This leather strip will have been initially provided with the series of spaced elongated picker rod holes 17 which are to be. located centrally of the loops.

Either before or after assembly of the softened leather with one or more layers of fabric, which may be either free or cemented to the leather, the leather strip is shaped with the aid of a device (Fig. 2) comprising seven steel pegs 22, 23 and 28 suitably mounted in two parallel lines on a board or bench 24. These pegs are somewhat higher than the width of the strap and they are preferably evenly spaced, as indicated in Fig. 2, so as to locate correctly the central portions of each of the loops of the corrugated shape. The pliable and flexible strap is formed on the peg board 24 by placin: the end 26 in position against a first peg 22, and the strip is bent around the second peg 23 and then in turn looped around the third peg and so on down the board, thus forming the non-contiguous, non-angular loops correctly shaped with smoothly merging curved surfaces and adapted for their subsequent bumper action. Instead of being placed inside of the last peg 28, the leather strip may be looped around it and brought back into contact with the first peg 22, the opposite side of which holds in place the end 26 of the strap, thus forming the retaining portion 15, 16. This brings the holes 17, 17 into alignment and while the soft and pliable strap is held by the pegs, a wooden or other suitable dowel pin 18 is inserted into the holes. This pin is long enough so that it projects well beyond the ends of the preformed strap and holds the strap shape thereafter. Because of its resiliency, the strap necessarily binds against the dowel pin and secures it in place.

The formed strap is then dried at room temperature or with the aid of heat, and preferably air dried, whilemounted on the pegs or separately on the pin 18 alone, and the water or other softening agent is evaporated, so as to leave the leather in a stiifly resilient condition. Thus the leather in this final form and texture, after regaining its stiffness, is held in a preformed shape with its loops out of contact and substantially in their picker rod shape, so that it may be readily slid from the pin 18 onto the picker rod of the loom. The dowell pin 18 is normally left in place during storage and sale and until the strap is to be used, so as to maintain a correct shape for the loops of the strap. The strap may be held in shape by other suitable means.

Since there may be a chance for accidental contact of the strap with oil, or the textile mill may have a humid atmosphere which penetrates the leather of the strap and the deposited water tends to soften the leather and decrease its resiliency or stiffness, I preferably coat the strap with a compound which is impervious to water and machine oils in at least the outer fibre portions of the strap and form a coating 39 (Fig. 3) on the exposed surfaces. A suitable coating and impregnating agent is polychloroprene or neoprene or a natural rubber, applied as a latex having, for example, 50% of latex in a body of water. Also, a soft thermosetting plastic resin, such as vinyl acetate or other suitable polymer in acetone or other solvent, may be employed. Neoprene is particularly resistant to the standard oils used for lubricating the loom. Various other materials that are compatible with the leather and the intermediate resilient layer 12, if used, may be employed. The synthetic or the natural rubber latex is preferred. After impregnation of the leather and coating of the exposed surfaces, the latex water is removed by evaporation in accordance with standard procedure, as by drying the body at room temperature. This leaves the rubber deposited within the outer surface pores and openings of the leather, and the fabric strip if used, and provides a highly impervious body, wherein the synthetic or natural rubber serves primarily as a coating agent which keeps out water and oils. The dowel pin 18 may be removed for this coating operation so that all exposed surfaces are covered. Then the dowel pin may be reinserted to hold the strap in its preformed condition. The coating is preferably applied POI'C spaces.

as soon as the strap has been dried and before it has absorbed a material amount of water. Various other expedients may be employed.

It will be understood that the leather in its final preshaped corrugated form has the stifily resilient texture imparted by air drying a leather body which has been softened by water or other suitable solvent to a condition where its fibres may be readily bent and the leather strip shaped in closely spaced but non-contiguous loops. in that condition, the leather does not possess the same properties as before the softening treatment but has the stiffness of a dried leather after a prolonged water immersion and impregnation.

The leather will have been previously tanned with a suitable or standard tanning agent, such as basic chromium sulfate or a tannin found in a vegetable tanning agent. In its original condition prior to the treatment herein specified, the ordinary tanned leather may contain approximately 5 to 10% of water. The tannin molecules are believed to be adsorbed on the surface of the collagen molecules of the leather and may serve as a bond therebetween. When this tanned leather is immersed in water, the water treatment is preferably carried on for a suitable time, such as 5 minutes or more, so that 30 to 50% and preferably at least 40% by weight of water is absorbed, or wherein the water content is about the same as the leather content. The tanning agent is soluble in the high water content, and enough agent is dissolved to loosen it from its adsorbed or coated condition on the collagen. In this condition, the tanning material that has been removed at least in part from the adsorbed location or intimate relation to the collagen is present in a free or suspended state within the leather This makes the leather body far more flexible and supple, and it may be bent as above described into the required shape. When the leather is again dried by the evaporation of the water, the tanning material becomes redistributed by deposition in new 10- cations within the leather body. Thus the structure has been permanently altered. The leather is ultimately dried to a condition of preferably 5 to 10% of water content, herein considered a dry leather. If the dry leather is soon thereafter treated with a rubber latex or emulsion, then as the water evaporates the rubber is drawn into the pore spaces of the leather and thus makes a thorough contact therewith and forms a highly protective water-proof and oil-proof coating which retains the leather in its altered structure.

It will be appreciated, in view of the above disclosure, that various modifications may be made in the device and the method of manufacture and that the above description of preferred embodiments and method of manufacture is not to be interpreted as imposing unnecessary limitations on the claim.

I claim:

As an article of commerce, a loom picker rod bumper strap comprising a continuous strip of tanned leather having free ends and preshaped as a single corrugated body having a multiplicity of spaced, non-contiguous, alternately extending, non-angular loops of curved portions merging with transverse portions provided with substantially aligned perforations and shaped for a free resiliently compressive sliding movement of all loops on a picker rod, said body having a U-shaped extension extending from the loop at one end of the strap around the corrugation loops and so arranged that both free ends of the body are contiguous and have adjacent perforations for mounting on the rod, the leather having the stifliy resilient, permanently altered, deformation resistant texture of a water impregnated and softened leather dried to a water content of not over 10% by weight, the entire corrugated portion of the strap having its loops preformed in substantially their final operative shape with all of the perforations arranged for directly sliding on the picker rod without requiring a material FOREIGN PATENTS bendmg 0f the straP- 406,115 Great Britain Feb. 22, 1934 References Cited in the file of this patent 578925 France June 1924 UNITED STATES PATENTS 5 2,499,596 Lesesne Mar. 7, 1950 2,532,543 Dodenhoff Dec. 5, 1950 2,616,454 Ahlstrand Nov. 4, 1952 2,646,083 Sahli July 21, 1953 

